Crosslinkable elastic copolymer composition

ABSTRACT

An elastic copolymer composition which contains a copolymer having a content of polymer units based on vinylidene fluoride as low as from 0.5 to 15 mol %, which is satisfactory in polyol vulcanizability and which gives a vulcanizate excellent in heat resistance and oil resistance. This composition comprises a tetrafluoroethylene (35 to 65 mol %)/propylene (20 to 50 mol %)/vinylidene fluoride (0.5 to 15 mol %) copolymer, an organic quaternary ammonium hydroxide or a salt of an organic quaternary phosphonium compound with a nitrogen-containing heterocyclic compound, an organic polyhydroxy compound, and a metal oxide or a metal hydroxide, and optionally contains an amine compound.

TECHNICAL FIELD

The present invention relates to a crosslinkable elastic copolymercomposition whereby polyol vulcanizability is excellent, and avulcanizate excellent in heat resistance and oil resistance can beobtained.

BACKGROUND ART

It is known that an elastic copolymer having vinylidene fluoride(hereinafter referred to as VdF) copolymerized, exhibits an excellentmold release property and gives a vulcanizate having excellent heatresistance, oil resistance and compression set, when an organicpolyhydroxy compound is used as a vulcanizing agent. Such a vulcanizateof an elastic copolymer is suitably used as an automobile part such asan oil seal. However, along with the trend for high performance ofengine oil, the durability against engine oil having a large amount ofan amine type additive incorporated, has become an important subject.

Especially, a vulcanizate of a composition containing a copolymer havinga content of polymer units based on VdF as high as at least 35 mol %,such as a hexafluoropropylene (hereinafter referred to as HFP)/VdF typeelastic copolymer or a HFP/VdF/tetrafluoroethylene (hereinafter referredto as TFE)type elastic copolymer, has had a problem such that the degreeof deterioration due to the reaction of the amine type additive to thesites of the polymer units based on VdF, is substantial.

Whereas, a vulcanizate of a composition containing a TFE/propylene(hereinafter referred to as P)/VdF type elastic copolymer as a copolymerhaving a low content (such as not higher than 15 mol %) of polymer unitsbased on VdF, is excellent in engine oil resistance. JP-A-6-157858discloses that by employing an organic quarternary ammonium bisulfate asa vulcanization accelerator, it is possible to obtain an excellentvulcanizate even with a TFE/P/VdF type elastic copolymer, which has acontent of polymer units based on VdF as low as 4 mol %. However, asshown in its Examples, a TFE/P/VdF type elastic copolymer having acontent of polymer units based on VdF at a level of not higher than 5mol %, has a vulcanization rate decreased as compared with a TFE/P/VdFtype elastic copolymer having such a content as high as at least 10 mol%. In fact, if a relatively large amount of an organic quarternaryammonium bisulfate is incorporated in order to increase thevulcanization rate, there has been an adverse effect to the heatresistance or oil resistance of the vulcanizate.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a crosslinkable elasticcopolymer composition which contains a TFE/P/VdF type elastic copolymerhaving a low content of polymer units based on VdF, which is excellentin polyol vulcanizability and which gives a vulcanizate excellent inheat resistance and oil resistance.

The present invention is firstly the following invention.

A crosslinkable elastic copolymer composition characterized in that itcomprises:

(A) an elastic copolymer comprising from 35 to 65 mol % of polymer unitsbased on TFE, from 20 to 50 mol % of polymer units based on P, and from0.5 to 15 mol % of polymer units based on VdF,

(B) at least one member selected from the group consisting of an organicquaternary ammonium hydroxide represented by the general formulaR¹R²R³R⁴NOH (wherein R¹ to R⁴ are the same or different C₁₋₂₀hydrocarbon groups) or the following formula 1 (wherein R⁵ is a hydrogenatom or a C₁₋₂₀ hydrocarbon group, and n is an integer of from 3 to 5),and a salt of an organic quaternary phosphonium compound with anitrogen-containing heterocyclic compound:

(C) at least one member selected from an organic polyhydroxy compoundand its derivative, and

(D) at least one member selected from a metal oxide and a metalhydroxide.

The present invention is secondly the following invention.

A crosslinkable elastic copolymer composition characterized in that itcomprises:

(A) an elastic copolymer comprising from 35 to 65 mol % of polymer unitsbased on TFE, from 20 to 50 mol % of polymer units based on P, and from0.5 to 15 mol % of polymer units based on VdF,

(B) at least one member selected from the group consisting of an organicquaternary ammonium hydroxide represented by the general formulaR¹R²R³R⁴NOH (wherein R¹ to R⁴ are the same or different C₁₋₂₀hydrocarbon groups) or the following formula 1 (wherein R⁵ is a hydrogenatom or a C₁₋₂₀ hydrocarbon group, and n is an integer of from 3 to 5),and a salt of an organic quaternary phosphonium compound with anitrogen-containing heterocyclic compound:

(C) at least one member selected from an organic polyhydroxy compoundand its derivative,

(D) at least one member selected from a metal oxide and a metalhydroxide, and

(E) an amine compound excluding the compound represented by the formula1.

BEST MODE FOR CARRYING OUT THE INVENTION

The Mooney viscosity ML₁₊₁₀ (121° C.) as an index of the molecularweight of the elastic copolymer of component (A) in the composition ofthe present invention, is not particularly limited, but it is preferablywithin a range of from 5 to 150, particularly preferably within a rangeof from 10 to 100, as a kneading operation is carried out usually at thetime of the preparation of the composition.

Component (A) wherein the proportion of polymer units based on VdF isfrom 0.5 to 15 mol %, preferably from 0.5 to 10 mol %, is capable ofgiving a vulcanizate which is excellent in engine oil resistance.Component (A) wherein the proportion of polymer units based on TFE isfrom 35 to 65 mol %, preferably from 45 to 65 mol %, has excellent heatresistance and chemical resistance and component (A) wherein theproportion of polymer units based on propylene is from 20 to 50 mol %,preferably from 35 to 50 mol %, is capable of giving a vulcanizatehaving excellent oil resistance.

Component (A) may contain or may not contain unsaturated bonds asreadily vulcanizable sites in the copolymer. By simply heat-treatingcomponent (A) or heat-treating it in the presence of a basic substanceor an acidic substance, it is possible to remove HF from polymer unitsbased on VdF and introduce carbon-carbon unsaturated bonds into thepolymer units. Further, unsaturated bonds may likewise be introduced bytreating a water dispersion of component (A) obtained by polymerization,with a basic substance such as potassium hydroxide. By introducing suchunsaturated bonds, the vulcanizability of component (A) can be improved.

The amount of unsaturated bonds to be introduced is preferably fromabout 1 to 50 mol % of the polymer units based on VdF. If the amount isless than this range, the effect for improvement of the vulcanizabilitytends to be small, and if it exceeds this range, the properties of theresulting vulcanizate may sometimes deteriorate.

For the production of the elastic copolymer of component (A), variouspolymerization systems may be employed such as bulk polymerization,suspension polymerization, emulsion polymerization or solutionpolymerization, and it is possible to optionally adopt a catalystpolymerization method employing a radical polymerization initiator, anionizing radiation polymerization method or a redox type polymerizationmethod.

Component (B) functioning as a vulcanization accelerator is at least onemember selected from the group consisting of an organic quaternaryammonium hydroxide represented by the general formula R¹R²R³R⁴NOH(wherein R¹ to R⁴ are the same or different C₁₋₂₀ hydrocarbon groups) orthe following formula 1 (wherein R⁵ is a hydrogen atom or a C₁₋₂₀hydrocarbon group, and n is an integer of from 3 to 5), and a salt of anorganic quaternary phosphonium compound with a nitrogen-containingheterocyclic compound:

Component (B) has an activity substantially higher than the organicquarternary ammonium bisulfate, and when component (B) is employed, anexcellent vulcanizate can be obtained even with a TFE/P/VdF type elasticcopolymer having a low content of polymer units based on VdF.

The following compounds may be exemplified as component (B). Thesecompounds may be used alone, respectively, or may be used in acombination of two or more of them.

The following may be exemplified as the organic quarternary ammoniumhydroxide represented by the above general formula R¹R²R³R⁴NOH or theformula (1) as component (B).

Tetrabutylammonium hydroxide, tetramethylammonium hydroxide,tetraethylammonium hydroxide, trioctylmethylammonium hydroxide,tridecylmethylammonium hydroxide, benzyltrimethylammonium hydroxide,8-benzyl-1,8-diazabicyclo[5.4.0]undeca-7-enium hydroxide,1,8-diazabicyclo[5.4.0]undeca-7-enium hydroxide,1,5-diazabicyclo[4.3.0]nona-5-enium hydroxide, etc.

Further, the flowing may be exemplified as the salt of an organicquarternary phosphonium compound with a nitrogen-containing heterocycliccompound, as component (B).

The salt of an organic quarternary phosphonium compound with anitrogen-containing heterocyclic compound, of component (B), contains anorganic quarternary phosphonium ion represented by the general formulaR⁶R⁷R⁸R⁹P⁺, wherein R⁶,R⁷,R⁸ and R⁹ may be the same or different andmay, for example, be a C₁₂₀ hydrocarbon group, such as an alkyl groupsuch as a methyl group, an ethyl group, a butyl group, an ethylhexylgroup or a dodecyl group, a cycloalkyl group such as a cyclohexyl group,an aralkyl group such as a benzyl group or a methylbenzyl group, or asubstituted or unsubstituted aryl group such as a phenyl group, anaphthyl group or a butylphenyl group, or a C₁₋₂₀ linear or branchedhalogenated hydrocarbon group such as a trifluoromethyl group or atrifluoroethyl group.

The nitrogen-containing heterocyclic compound in component (B) may, forexample, be a pyrroline, a morpholine, pyrrolidine, a pyrrole, apyrazole, a pyrazoline, an imidazole, an imidazoline, a benzotriazole, abenzoimidazole, an indoline, an indole, an isoindole, a purine or acarbazole. These nitrogen-containing heterocyclic compounds may havehydrocarbon groups, halogenated hydrocarbon groups, halogen atoms,hydroxyl groups or other substituents. A preferred nitrogen-containingheterocyclic compound is an imidazole, a benzoimidazole, a benzotriazoleor a carbazole, which may have the above-mentioned substituents.

The following may preferably be mentioned as the salt of an organicquarternary phosphonium compound with a nitrogen-containing heterocycliccompound, of component (B).

A benzotriazolate, such as tetrabutylphosphonium benzotriazolate,tetraoctylphosphonium benzotriazolate, methyltrioctylphosphoniumbenzotriazolate, butyltrioctylphosphonium benzotriazolate,phenyltributylphosphonium benzotriazolate, benzyltributylphosphoniumbenzotriazolate, benzyltricyclohexylphosphonium benzotriazolate,benzyltrioctylphosphonium benzotriazolate, butyltriphenylphosphoniumbenzotriazolate, octyltriphenylphosphonium benzotriazolate,benzyltriphenylphosphonium benzotriazolate, tetraphenylphosphoniumbenzotriazolate, 2,2,2,-trifluoroethyltributylphosphoniumbenzotriazolate or 2,2,3,3-tetrafluoropropyltrioctylphosphoniumbenzotriazolate; a benzoimidazolate such as tetrabutylphosphoniumbenzoimidazolate; an imidazolate such as tetrabutylphosphoniumimidazolate; a carbazolate such as tetrabutylphosphonium carbazolate.

Component (B) is used in an amount of from 0.1 to 10 parts by weight,preferably from 0.1 to 3 parts by weight, per 100 parts by weight of theelastic copolymer of component (A). If the amount is less than 0.1 partby weight, it tends to be difficult to obtain an adequate vulcanizationdensity and vulcanization properties, and if it exceeds 10 parts byweight, a scorching phenomenon or the like is likely to occur andadversely affect the molding operation, or the chemical resistance, etc.of the vulcanizate tend to deteriorate. Usually, the organic quarternaryammonium hydroxide is commercially available in the form of an aqueoussolution or an alcohol solution and will be used in that form.

As the organic polyhydroxy compound of component (C) which functions asa vulcanizing agent, an aromatic polyhydroxy compound having at leasttwo phenolic hydroxyl groups, is preferred, as it has high vulcanizationactivities. A compound having an alcoholic hydroxyl group may be used,but a particularly preferred organic polyhydroxy compound is an aromaticdihydroxy compound having two phenolic hydroxyl groups. Specifically,the following may preferably be exemplified as the organic polyhydroxycompound.

2,2-bis(4-hydroxyphenyl)propane [abbreviated name: bisphenol A],2,2-bis(4-hydroxyphenyl)perfluoropropane [abbreviated name: bisphenolAF], 1,3,5-trihydroxybenzene, 1,7-dihydroxynaphthalene,2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene,4,4′-dihydroxybiphenyl, catechol, p,p′-dihydroxystilbene,2,6-dihydroxyanthracene, hydroquinone, 2,2-bis(4-hydroxyphenyl)butane,2,2-bis(4-hydroxyphenyl)tetrafluorodichloropropane,4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenylketone,tris(4-hydroxyphenyl)methane, 2,2,3,3,4,4-hexafluoropentane-1,5-diol,ethylene glycol, polyethylene glycol, etc.

Further, as the derivative of an organic polyhydroxy compound ofcomponent (C) which functions as a vulcanizing agent, an alkali metalsalt or an alkaline earth metal salt of an organic polyhydroxy compound,or a salt thereof with an organic quarternary ammonium hydroxide ascomponent (B), may preferably be exemplified.

As component (C), such organic polyhydroxy compounds and theirderivatives may be used alone, respectively, or in a combination of twoor more of them. Usually, component (C) is used alone or as a mixture oftwo or more of them, and the amount is from 0.1 to 10 parts by weight,preferably from 0.5 to 5 parts by weight, per 100 parts by weight of theelastic copolymer of component (A). If it is too small, it tends to bedifficult to obtain an adequate crosslinking density, and if it is toomuch, the effects do not change.

The metal oxide or the metal hydroxide of component (D) which functionsas an acid-acceptor, may, for example, be an oxide of a bivalent metalsuch as magnesium, calcium, lead or zinc, a hydroxide of such a bivalentmetal, or lithium hydroxide. The amount of component (D) is from 1 to 50parts by weight, preferably from 2 to 30 parts by weight, per 100 partsby weight of the elastic copolymer of component (A). They may be used ina combination of two or more of them.

The amine compound of component (E) (excluding the compound representedby the above formula 1) to be used for improvement of the vulcanizationrate, may, for example, be 1,8-diazabicyclo[5.4.0]undeca-7-ene,1,5-diazabicyclo[4.3.0]nona-5-ene,6-dibutylamino-1,8-diazabicyclo[5.4.0]undeca-7-ene, triethylamine ortributylamine. The amount of component (E) is preferably from 0.01 to 3parts by weight, particularly preferably from 0.05 to 1 part by weight,per 100 parts by weight of the elastic copolymer of component (A). Theymay be used in a combination of two or more of them.

To the composition of the present invention, a reinforcing agent such ascarbon black, fine silica, clay or talc, which is commonly used for thepreparation of rubber, other fillers, pigments, antioxidants,stabilizers, processing aids or internal release agents, may, forexample, be added or blended.

For the preparation of the composition of the present invention, it isadvisable to adequately uniformly mix components (A), (B), (C), (D) and(E) and optionally other additives. Also, components (B) and (C) may beused as preliminarily mixed.

This mixing is carried out by means of a kneading roll, a kneader, aBanbury mixer, an extruder or the like, which has been commonlyemployed. The operation conditions for the mixing are not particularlylimited. However, the additives can be dispersed in the elasticcopolymer usually by kneading at a temperature of from about 30 to 130°C. for about 1 to 60 minutes. Such an additives may be dissolved anddispersed in a suitable solvent and mixed as a suspension solution.

Further, a so-called wet mixing may be adopted, whereby the mixing iscarried out in a medium from the very beginning. In such a case, acomposition in the form of a solution can be obtained by means of amixing machine such as a roll, ball mill or homogenizer. Otherwise, bymixing component (B) to a water dispersion of component (A) obtainableby polymerization, component (B), etc., can be dispersed moreeffectively. Further, with respect to the processing conditions for themixing, it is advisable to select the optimum conditions depending uponthe purpose or the types of the blend and the starting materials used.

The composition of the present invention may be molded into a moldedproduct such as a sheet, a pipe, a rod, a tube, an angle, a channel, acoated cloth or a coated plate, by a continuous molding method such ascompression molding, injection molding, extrusion molding, transfermolding, roll coating, brush coating or impregnation. Further, it may bemolded into unusual shapes or special shapes, such as spongy rubber,etc., by other various molding methods. The composition of the presentinvention thus molded, is vulcanized by a vulcanization operation asdescribed hereinafter.

Thus, from the composition of the present invention, a rubber productwhich is a vulcanizate, will be obtained. In the present invention, as aprocedure for vulcanization, a procedure which has been commonly used,may be employed. For example, it is possible to employ a procedure ofheating while pressurizing in a mold, or a procedure of molding by e.g.extrusion, calendaring roll or injection molding, followed by heating ina heating oven or the like. With respect to the vulcanizationconditions, it is advisable to select optimum conditions depending uponthe blend, molding conditions, etc. The vulcanization temperature isusually from about 100 to 400° C., preferably from about 150 to 200° C.Further, the vulcanization time is within a range of from about 30seconds to a few hours. Further, the obtained vulcanizate may besubjected to secondary vulcanization. By the secondary vulcanization,the physical properties may sometimes be improved. The conditions forthe secondary vulcanization are not particularly limited and may besuitably selected depending upon the shape or size of the moldedproduct, etc. They are from 150 to 250° C., preferably from 180° C. to230° C., and from about 2 to 25 hours. With a TFE/P/VdF type elasticcopolymer having a low content of polymer units based on VdF, polyolvulcanization will readily proceed by employing as a vulcanizationaccelerator an organic quarternary ammonium hydroxide or a salt of anorganic quarternary phosphonium compound with a nitrogen-containingheterocyclic compound, of the above-mentioned component (B), or by acombined use thereof with an amine compound of the above-mentionedcomponent (E). Further, the resulting vulcanizate will be excellent inheat resistance and oil resistance, since the content of polymer unitsbased on VdF is low.

Now, the present invention will be described in further detail withreference to Examples and Comparative Examples. However, the presentinvention is by no means restricted by them.

Examples 1 to 6 represent Examples of the present invention, andExamples 7 to 10 represent Comparative Examples. Materials blended tohave a composition as identified in Table 1 or 2 were uniformly mixed bya twin roll to obtain a crosslikable elastic copolymer composition. Withrespect to the vulcanization properties of this composition, the lowesttorque (M_(L)) and the highest torque (M_(H)) at 170° C. for 24 minutes,and the time t_(c) (90) until the torque value reached 90% of thehighest torque value, were measured by means of an oscillating diskrheometer (manufactured by Toyo Seiki). Further, this composition wassubjected to press vulcanization at 170° C. for 20 minutes, and thensubjected to secondary vulcanization at 230° C. for 24 hours in an oven.

With respect to the obtained vulcanizate, in accordance with JIS K6301,the original physical properties, the heat resistance (at 230° C. for 70hr) and the oil resistance (at 175° C. for 70 hr) were measured. For themeasurement of the oil resistance, SH grade engine oil (Castle Motor OilClean SH, manufactured by Toyota Automobile) was employed. The resultsare shown in Tables 3 and 4. Symbol “*” in the Tables indicates that novulcanized sheet was obtained.

Abbreviations, etc. in Tables 1 and 2 are shown in Table 5. Further, therespective elastic copolymers used, were prepared by emulsionpolymerization, and their contents (mol %) of polymer units based on therespective monomers, and the Mooney viscosity ML₁₊₁₀ (121° C.) are alsoshown in Table 5. The compositions of polymer units based on therespective monomers of component (A) were obtained by ¹⁹F-NMR and¹H-NMR. Further, unsaturated bonds in the elastic copolymer 5 wereconfirmed to be present by the absorption at wave numbers of 3120 cm⁻¹and 1722 cm⁻¹ by the infrared analysis.

TABLE 1 Unit: Parts by weight Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6Elastic 100 copolymer 1 Elastic 100 copolymer 2 Elastic 100 100copolymer 3 Elastic 100 copolymer 4 Elastic 100 copolymer 5 MT carbonblack 25 25 25 25 25 25 Kyowa mag 150 3 3 3 3 3 3 Calvit 3 3 3 3 3 3Bisphenol AF 1.5 1.5 1.5 1.5 1.5 1.5 TBAOH 0.5 0.5 0.9 1.2 1 BTMAOH 1

TABLE 2 Unit: Parts by weight Ex. 7 Ex. 8 Ex. 9 Ex. 10 Elastic 100 100copolymer 3 Elastic 100 100 copolymer 4 MT carbon black 25 25 25 25Kyowa mag 150 3 3 3 3 Calvit 3 3 3 3 Bisphenol AF 1.5 1.5 1.5 1.5 TBAHS0.7 1.3 1.3 TOMAHS 2

TABLE 3 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Vulcanization properties(170° C. × 24 min) M_(L) (kg · cm) 7 7 8 7 8 7 M_(n) (kg · cm) 45 45 4639 44 48 t_(c) (90) (min) 6.2 7.2 7.1 7.7 7.2 7.3 Original physicalproperties Hardness (JIS-A) 72 72 73 73 73 73 100% Modulus (kg · f/cm²)65 70 73 48 77 80 Tensile strength (kg · f/cm²) 180 175 183 160 175 188Elongation (%) 270 250 223 280 230 215 Compression set 22 23 25 27 27 22(%, 200° C. × 70 hr) Heat resistance (230° C. × 70 hr) Hardness change(degree) +2 +1 +2 +1 +1 +1 Tensile strength change (%) +4 +7 +3 +11 +2+5 Elongation change (%) −11 −8 −6 −10 −9 −8 Oil resistance (175° C. ×70 hr) Hardness change (degree) −2 −1 −1 0 −1 −1 Tensile strength change(%) −10 −8 −2 −5 −5 −3 Elongation change (%) −12 −8 −3 +5 +2 0 Volumechange (%) +3 +3 +5 +6 +5 +5

TABLE 4 Ex. 7 Ex. 8 Ex. 9 Ex. 10 Vulcanization properties (170° C. × 24min) M_(L) (kg · cm) 5 7 7 5 M_(n) (kg · cm) 35 40 12 18 t_(C) (90)(min) 15.8 7.7 22.5 21.5 Original physical properties Hardness (JIS-A)75 77 * 68 100% Modulus (kg · f/cm²) 48 68 35 Tensile strength (kg ·f/cm²) 161 173 121 Elongation (%) 230 210 380 Compression set 24 28 55(%, 200° C. × 70 hr) Heat resistance (230 ° C. × 70 hr) Hardness change+4 +6 +7 (degree) Tensile strength +18 +10 +40 change (%) Elongationchange (%) −15 −28 −42 Oil resistance (175° C. × 70 hr) Hardness change0 +3 +6 (degree) Tensile strength +5 +15 +37 change (%) Elongationchange (%) −8 −20 −46 Volume change (%) +6 +6 +8

TABLE 5 Elastic VdF/TFE/P = 15/50/35, (ML₁₊₁₀ = 60) copolymer 1 ElasticVdF/TFE/P = 10/55/35, (ML₁₊₁₀ = 52) copolymer 2 Elastic VdF/TFE/P =4/52/44, (ML₁₊₁₀ = 44) copolymer 3 Elastic VdF/TFE/P = 1/54/45, (ML₁₊₁₀= 35) copolymer 4 Elastic Copolymer having unsaturated bonds introducedcopolymer 5 into Elastic copolymer 4 (ML₁₊₁₀ = 35) Kyowa mag 150Magnesium oxide (manufactured by Kyowa Chemical Industry) Calvit Calciumhydroxide (manufactured by Ohmi Chemical) Tetrabutylammonium hydroxide(used as a methanol solution having a 40% TBAOH concentration.) Theamounts by parts in Tables are calculated as solid content oftetrabutylammonium hydroxide. Benzyltrimethylammonium hydroxide (used asa methanol solution having a 40% BTMAOH concentration.) The amounts byparts in Tables are calculated as solid content ofbenzyltrimethylammonium hydroxide TBAHS Tetrabutylammonium bisulfateTOMAHS Trioctylmethylammonium bisulfate

Examples 11 to 17 represent Examples of the present invention, andExamples 18 to 21 represent Comparative Examples. Materials blended tohave a composition (parts by weight) shown in Table 6 or 7 wereuniformly mixed by a twin roll to obtain a crosslikable elasticcopolymer composition. With respect to this composition, thevulcanization properties i.e. the lowest torque (M_(L)) and the highesttorque (M_(H)) at 170° C. for 24 minutes, and the time t_(c) (90) untilthe torque value reached 90% of the highest torque value, were measuredby means of an oscillating disk rheometer (manufactured by Toyo Seiki).Further, this composition was subjected to press vulcanization at 170°C. for 20 minutes, and then subjected to secondary vulcanization at 230°C. for 24 hours in an oven. In Example 20, no vulcanized sheet wasobtained even if press vulcanization was carried out at 170° C. for 20minutes.

With respect to the obtained vulcanizate, in accordance with JIS K6301,the original physical properties, the compression set (200° C., 70 hr),the heat resistance (230° C., 70 hr) and the oil resistance (the samplewas immersed in an oil at 175° C. for 70 hours) were measured. For themeasurement of the oil resistance, SH grade engine oil (Castle Motor OilClean SH, manufactured by Toyota Automobile) was used. The results areshown in Tables 8 and 9.

Abbreviations, etc. in Tables 6 and 7 are shown in Table 10. Further,the respective elastic copolymers used were prepared by emulsionpolymerization, and their contents (molar ratio) of polymer units basedon the respective monomers, and the Mooney viscosity ML₁₊₁₀ (121° C.)are shown in Table 10. The compositions of polymer units based on therespective monomers of component (A) were obtained by ¹⁹F-NMR and¹H-NMR. Unsaturated bonds in the elastic copolymer (e) obtained by heattreating the elastic copolymer (d) at 290° C. for one hour, wereconfirmed to be present by the absorption at wave numbers of 3120 cm⁻¹and 1722 cm⁻¹ by the infrared analysis.

TABLE 6 Unit: Parts by weight Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 Ex. 16Elastic 100 copolymer (a) Elastic 100 copolymer (b) Elastic 100 100copolymer (c) Elastic 100 copolymer (d) Elastic 100 copolymer (e) MTcarbon 25 25 25 25 25 25 black Kyowa mag 3 3 3 3 3 3 150 Calvit 3 3 3 33 3 Bisphenol AF 1.5 1.5 1.5 1.5 1.5 1.5 TBAOH 0.5 0.5 0.9 1.2 1 BTMAOH1 DBU 0.1 0.1 0.1 0.1 0.1 0.1

TABLE 7 Unit: Parts by weight Ex. 17 Ex. 18 Ex. 19 Ex. 20 Ex. 21 Elasticcopolymer (c) 100 100 100 Elastic copolymer (d) 100 100 MT carbon black25 25 25 25 25 Kyowa mag 150 3 3 3 3 3 Calvit 3 3 3 3 3 Bisphenol AF 1.51.5 1.5 1.5 1.5 TBAHS 0.9 TOMAHS 0.7 1.3 1.3 Trioctylmethyl 0.3 ammoniumbisulfate DBU 0.3

TABLE 8 Ex. Ex. Ex. Ex. Ex. Ex. 11 12 13 14 15 16 Vulcanizationproperties (170° C. × 24 min) M_(L) (kg · cm) 7 7 8 8 9 8 M_(H) (kg ·cm) 46 47 48 42 46 48 t_(c) (90) (min) 5.0 6.1 5.9 6.4 6.1 6.0 Originalphysical properties Hardness (JIS-A) 73 73 74 74 74 73 100% Modulus (kg· f/cm²) 70 76 80 59 85 82 Tensile strength (kg · f/cm²) 185 180 185 175175 180 Elongation (%) 250 230 210 265 220 210 Compression set 24 25 2625 25 24 (%, 200° C. × 70 hr) Heat resistance (230° C. × 70 hr) Hardnesschange (degree) +3 +2 +2 +2 +1 +1 Tensile strength change (%) +2 +7 +5+10 +8 +7 Elongation change (%) −14 −10 −8 −12 −7 −5 Oil resistance(175° C. × 70 hr) Hardness change (degree) −3 −2 −3 −2 −3 −2 Tensilestrength change (%) −10 −11 −8 −5 −4 −9 Elongation change (%) −15 −10 +2−10 +5 +1 Volume change (%) +3 +3 +6 +5 +6 +5

TABLE 9 Ex. 17 Ex. 18 Ex. 19 Ex. 20 Ex. 21 Vulcanization properties(170° C. × 24 min) M_(L) (kg · cm) 9 5 7 7 5 M_(H) (kg · cm) 50 35 40 1218 t_(c (90) (min)) 5.1 15.8 7.7 22.5 21.5 Original physical propertiesHardness (JIS-A) 76 75 77 68 100% Modulus 90 48 68 35 (kg · f/cm²)Tensile strength 195 161 173 121 (kg · f/cm²) Elongation (%) 195 230 210380 Compression set (%, 200° C. × 70 hr) 23 24 28 55 Heat resistance(230° C. × 70 hr) Hardness change +2 +4 +6 +7 (degree) Tensile strength+2 +18 +10 +40 change (%) Elongation change (%) −14 −15 −28 −42 Oilresistance (175° C. × 70 hr) Hardness change −4 0 +3 +6 (degree) Tensilestrength −10 +5 +15 +37 change (%) Elongation change (%) −3 −8 −20 −46Volume change (%) +6 +6 +6 +8

TABLE 10 Elastic VdF/TFE/P = 15/50/35, (ML₁₊₁₀ = 60) copolymer (a)Elastic VdF/TFE/P = 10/55/35, (ML₁₊₁₀ = 52) copolymer (b) ElasticVdF/TFE/P = 4/52/44, (ML₁₊₁₀ = 44) copolymer (c) Elastic VdF/TFE/P =1/54/45, (ML₁₊₁₀ = 35) copolymer (d) Elastic Elastic copolymer (d)obtained by heat treating copolymer (e) the at 290° C. for one hour(ML₁₊₁₀ = 30) Magnesium oxide Kyowa mag 150 (manufactured by KyowaChemical Industry) Calvit Calcium hydroxide (manufactured by OhmiChemical) Tetrabutylammonium hydroxide (used as a methanol solutionhaving a 40% TBAOH concentration.) The amounts by parts in Tables arecalculated as solid content of tetrabutylammonium hydroxide.Benzyltrimethylammonium hydroxide (used as a methanol solution having a40% BTMAOH concentration.) The amounts by parts in Tables are calculatedas solid content of benzyltrimethylammonium hydroxide. TBAHSTetrabutylammonium bisulfate TOMAHS 1,8-diazabicyclo[5.4.0]undeca-7-ene

Examples 22 to 28 represent Examples of the present invention, andExamples 29 to 32 represent Comparative Examples. Materials blended tohave a composition (unit: parts by weight) shown in Table 11 or 12 wereuniformly mixed by a twin roll to obtain a crosslikable elasticcopolymer composition. With respect to the vulcanization properties ofthis composition, the lowest torque (M_(L)) and the highest torque(M_(H)) at 170° C. for 24 minutes, and the time t_(c) (90) until thetorque value reached 90% of the highest torque value, were measured bymeans of an oscillating disk rheometer (manufactured by Toyo Seiki).Further, this composition was subjected to press vulcanization at 170°C. for 20 minutes, and then subjected to secondary vulcanization by heattreatment at 230° C. for 24 hours in an oven.

With respect to the obtained vulcanizate, in accordance with JIS K6301,the original physical properties, the heat resistance (at 230° C. for 70hr), the oil resistance (at 175° C. for 70 hr) were measured. For themeasurement of the oil resistance, SH grade engine oil (Castle Motor OilClean SH, manufactured by Toyota Automobile) was employed. The resultsare shown in Tables 13 and 14. Symbol “*” in the Tables represents thatno vulcanized sheet was obtained.

Abbreviations, etc. in Tables 11 and 12 are shown in Table 15. Further,the respective elastic copolymers used were prepared by emulsionpolymerization, and their contents (mol %) of polymer units based on therespective monomers, and the Mooney viscosity ML₁₊₁₀ (121° C.) are alsoshown in Table 15. The compositions of polymer units based on therespective monomers of component (A) were obtained by ¹⁹F-NMR and¹H-NMR. Further, unsaturated bonds in the elastic copolymer (j) wereconfirmed to be present by the absorption at wave numbers of 3120 cm⁻¹and 1722 cm⁻¹ by the infrared analysis.

TABLE 11 Ex. Ex. Ex. Ex. Ex. Ex. Ex. Unit: Parts by weight 22 23 24 2526 27 28 Elastic copolymer (f) 100 Elastic copolymer (g) 100 Elasticcopolymer (h) 100 100 100 Elastic copolymer (i) 100 Elastic copolymer(j) 100 MT carbon black 25 25 25 25 25 25 25 Kyowa mag 150 3 3 3 3 3 3 3Calvit 6 6 6 6 6 6 6 Bisphenol AF 1.5 1.5 1.5 1.5 1.5 1.5 1.5 TBPBT 0.40.3 0.6 1.2 1 TBPBI 0.6 TBPI 0.6

TABLE 12 Unit: Parts by weight Ex. 29 Ex. 30 Ex. 31 Ex. 32 Elasticcopolymer (i) 100 100 Elastic copolymer (j) 100 100 MT carbon black 2525 25 25 Kyowa mag 150 3 3 3 3 Calvit 3 3 3 3 Bisphenol AF 1.5 1.5 1.51.5 TBAHS 0.7 1.3 1.3 TOMAHS 2

TABLE 13 Ex. Ex. Ex. Ex. Ex. Ex. Ex. 22 23 24 25 26 27 28 Vulcanizationproperties (170° C. × 24 min) M_(L) (kg · cm) 7 7 8 7 7 8 8 M_(H) (kg ·cm) 45 45 47 43 43 45 45 t_(c) (90) (min) 6.3 6.8 7.1 7.4 6.2 7.2 6.3Original physical properties Hardness (JIS-A) 71 72 71 69 73 72 71 100%Modulus 52 65 61 47 77 65 53 (kg · f/cm²) Tensile strength 184 182 196175 170 185 185 (kg · f/cm²) Elongation (%) 257 223 239 250 245 220 210Compression set 24 24 25 29 27 26 25 (%, 200° C. × 70 hr) Heatresistance (230° C. × 70 hr) Hardness change +2 +1 +2 +2 +1 +2 +2(degree) Tensile strength −5 −6 −5 −7 −5 −8 −9 change (%) ElongationChange −12 −8 −9 −12 −10 −13 −14 (%) Oil resistance (175° C. × 70 hr)Hardness change −3 −4 −3 −2 −2 −2 −3 (degree) Tensile strength −11 −9−14 −8 −9 −10 −15 change (%) Elongation Change −14 −11 −12 −15 −18 −17−10 (%) Volume change (%) +3 +4 +6 +6 +6 +6 +6

TABLE 14 Ex. 29 Ex. 30 Ex. 31 Ex. 32 Vulcanization properties (170° C. ×24 min) M_(L) (kg · cm) 5 7 7 5 M_(H) (kg · cm) 35 40 12 18 t_(c) (90)(min) 15.8 7.7 22.5 21.5 Original physical properties Hardness (JIS-A)75 77 * 68 100% Modulus (kg · f/cm²) 48 68 35 Tensile strength (kg ·f/cm²) 161 173 121 Elongation (%) 230 210 380 Compression set (%, 200°C. × 70 hr) 24 28 55 Heat resistance (230° C. × 70 hr) Hardness change+4 +6 +7 (degree) Tensile strength +18 +10 +40 change (%) Elongationchange (%) −15 −28 −42 Oil resistance (175° C. × 70 hr) Hardness change0 +3 +6 (degree) Tensile strength +5 +15 +37 change (%) Elongationchange (%) −8 −20 −46 Volume change (%) +6 +6 +8

TABLE 15 Elastic VdF/TFE/P = 15/50/351 (ML₁₊₁₀ = 60) copolymer (f)Elastic VdF/TFE/P = 10/55/351 (ML₁₊₁₀ = 52) copolymer (g) ElasticVdF/TFE/P = 4/52/44, (ML₁₊₁₀ = 44) copolymer (h) Elastic VdF/TFE/P =1/54/451 (ML₁₊₁₀ = 35) copolymer (i) Elastic Copolymer havingunsaturated bonds introduced copolymer (j) into Elastic copolymer (i)(ML₁₊₁₀ = 40) Magnesium oxide Kyowa mag 150 (manufactured by KyowaChemical Industry) Calcium hydroxide Calvit (manufactured by OhmiChemical) Tetrabutylphosphonium benzotriazolate (used as a 50% aqueoussolution) The TBPBT amounts by parts in Tables are calculated as solidcontent of tetrabutylphosphonium benzotriazolate Tetrabutylphosphoniumbenzoimidazolate (used as a 50% aqueous solution) The TBPBI amounts byparts in Tables are calculated as solid content of tetrabutylphosphoniumbenzoimidazolate. Tetrabutylphosphonium benzoimidazolate (used as a 50%methanol solution) The TBPI amounts by parts in Tables are calculated assolid content of tetrabutylphosphonium benzoimidazolate TOMAHSTrioctylmethylammonium bisulfate TBAHS Tetrabutylammonium bisulfate

The composition containing a TFE/P/VdF type elastic copolymer having alow content of polymer units based on VdF exhibits excellent polyolvulcanizability and gives a vulcanizate excellent in heat resistance andoil resistance. Further, the vulcanizate has various excellent physicalproperties of vulcanizate and is very useful for a wide range ofapplications including O-rings, gaskets, sealing materials, diaphragms,tubes, hoses, etc. for radiators and engines of automobiles, and similarparts for e.g. food plants, chemical plants, etc.

What is claimed is:
 1. A composition, comprising: (A) an elasticcopolymer comprising from 35 to 65 mol %, of polymer units based ontetrafluoroethylene, from 20 to 50 mol % of polymer units based onpropylene, and from 0.5 to 15 mol % of polymer units based on vinylidenefluoride; (B) one member selected from the group consisting of (i) anorganic quaternary ammonium hydroxide represented by the general formulaR¹R²R³R⁴NOH  wherein R¹ to R⁴ are the same or different C₁₋₂₀hydrocarbon groups, (ii) an organic quaternary ammonium hydroxiderepresented by formula 1:

 wherein R⁵ is a hydrogen atom or a C₁₋₂₀ hydrocarbon group and n is aninteger of from 3 to 5, and (iii) a salt of an organic quaternaryphosphonium compound with a nitrogen-containing heterocyclic compound;(C) at least one member selected from the group consisting of an organicpolyhydroxy compound and its derivative; and (D) at least one memberselected from the group consisting of metal oxide and a metal hydroxide.2. The composition according to claim 1, further comprising an aminecompound excluding the compound represented by the formula
 1. 3. Thecomposition according to claim 1, further comprising a tertiary amineexcluding the compound represented by the formula
 1. 4. The compositionaccording to claim 1, further comprising one member selected from thegroup consisting of 1,8-diazabicyclo[5.4.0]undeca-7-ene,1,5-diazabicyclo[4.3.0]nona-5-ene,6-dibutylamino-1,8-diazabicyclo[5.4.0]undeca-7-ene, triethylamine, andtributylamine.
 5. A composition, comprising: (A) an elastic copolymercomprising from 35 to 65 mol %, of polymer units based ontetrafluoroethylene, from 20 to 50 mol % of polymer units based onpropylene, and from 0.5 to 15 mol % of polymer units based on vinylidenefluoride; (B) one member selected from the group consisting of (i) anorganic quaternary ammonium hydroxide represented by the general formulaR¹R²R³R⁴NOH  wherein R¹ to R⁴ are the same or different C₁₋₂₀hydrocarbon groups, (ii) an organic quaternary ammonium hydroxiderepresented by formula 1:

 wherein R⁵ is a hydrogen atom or a C₁₋₂₀ hydrocarbon group and n is aninteger of from 3 to 5, and (iii) a salt of an organic quaternaryphosphonium compound with a nitrogen-containing heterocyclic compound;(C) at least one member selected from the group consisting of an organicpolyhydroxy compound and its derivative; (D) at least one memberselected from the group consisting of metal oxide and a metal hydroxide;and (E) an amine compound excluding the compound represented by theformula
 1. 6. The composition according to claim 5, wherein component(E) is a tertiary amine excluding the compound represented by theformula
 1. 7. The composition according to claim 5, wherein component(E) is one member selected from the group consisting of1,8-diazabicyclo[5.4.0]undeca-7-ene, 1,5-diazabicyclo[4.3.0]nona-5-ene,6-dibutylamino-1,8-diazabicyclo[5.4.0]undeca-7-ene, triethylamine, andtributylamine.
 8. A composition, comprising: (A) an elastic copolymercomprising from 35 to 65 mol %, of polymer units based ontetrafluoroethylene, from 20 to 50 mol % of polymer units based onpropylene, and from 0.5 to 15 mol % of polymer units based on vinylidenefluoride; (B) one member selected from the group consisting of (i) anorganic quaternary ammonium hydroxide represented by the general formulaR¹R²R³R⁴NOH  wherein R¹ to R⁴ are the same or different C₁₋₂₀hydrocarbon groups, (ii) an organic quaternary ammonium hydroxiderepresented by formula 1:

 wherein R⁵ is a hydrogen atom or a C₁₋₂₀ hydrocarbon group and n is aninteger of from 3 to 5, and (iii) a salt of an organic quaternaryphosphonium compound with a nitrogen-containing heterocyclic compound;(C) at least one member selected from the group consisting of an organicpolyhydroxy compound and its derivative; (D) at least one memberselected from the group consisting of metal oxide and a metal hydroxide;and (E) one member selected from the group consisting of1,8-diazabicyclo[5.4.0]undeca-7-ene, 1,5-diazabicyclo[4.3.0]nona-5-ene,6-dibutylamino-1,8-diazabicyclo[5.4.0]undeca-7-ene, triethylamine, andtributylamine.
 9. A composition, comprising: (A) an elastic copolymercomprising from 35 to 65 mol %, of polymer units based ontetrafluoroethylene, from 20 to 50 mol % of polymer units based onpropylene, and less than 10.0 mol % of polymer units based on vinylidenefluoride; (B) at least one member selected from the group consisting of(i) an organic quaternary ammonium hydroxide represented by the generalformula R¹R²R³R⁴NOH  wherein R¹ to R⁴ are the same or different C₁₋₂₀hydrocarbon groups, (ii) an organic quaternary ammonium hydroxiderepresented by formula 1:

 wherein R⁵ is a hydrogen atom or a C₁₋₂₀ hydrocarbon group and n is aninteger of from 3 to 5, and (iii) a salt of an organic quaternaryphosphonium compound with a nitrogen-containing heterocyclic compound;(C) at least one member selected from the group consisting of an organicpolyhydroxy compound and its derivative; and (D) at least one memberselected from the group consisting of a metal oxide and a metalhydroxide.
 10. The composition according to claim 9, further comprisingan amine compound excluding the compound represented by the formula 1.11. The composition according to claim 9, further comprising a tertiaryamine excluding the compound represented by the formula
 1. 12. Thecomposition according to claim 9, further comprising one member selectedfrom the group consisting of 1,8-diazabicyclo[5.4.0]undeca-7-ene,1,5-diazabicyclo[4.3.0]nona-5-ene,6-dibutylamino-1,8-diazabicyclo[5.4.0]undeca-7-ene, triethylamine, andtributylamine.